The present invention generally relates to occluders for flexible tubing that prevent fluid flow through a portion of tubing. The present invention specifically relates to the selective occluding of an intravenous (IV) tube used to infuse liquid medication to a patient.
Intravenous infusion of medical solutions to patients is well known in the medical profession. Such infusion devices typically use a pump, such as a peristaltic pump, to create a moving zone of occlusion along a portion of an IV tube to administer fluid to a patient. The danger inherent in the use of the IV tube with a pump is that unwanted fluid will flow to the patient. Typically, the times of greatest concern for this danger are during the initial set-up of the IV administration system and at any subsequent time when the IV tube is connected between the fluid source and the patient and the IV tube becomes disengaged from the infusion device for some reason.
Various devices to constrict or occlude flow of liquid through tubes are described in the prior art. Typical devices include manually operated slide clamps. Roller clamps, such as the one described in U.S. Pat. No. 3,189,038, are one such example. A slide clamp of typical design is also described in U.S. Pat. No. 2,889,848. Both of these clamps are multi-element assemblies and both must be activated independently and separately from any medical device which may be operatively attached to the IV fluid line.
The need to coordinate the operation of a clamp or occluder with an associated medical device, such as a peristaltic pump has been recognized in the prior art as well. U.S. Pat. No. 4,586,691 discloses a safety slide clamp that requires the cooperation of structure between the device and the slide clamp itself. Another prior art slide clamp for an IV tube associated with an IV infusion pump is disclosed in U.S. Pat. No. 4,689,043. This device includes a peristaltic pump enclosed in a housing with a door and a door mounted handle for operatively engaging and disengaging the slide clamp. The disclosed clamp, however, includes several elements, each of which may require precision machine tolerances. U.S. Pat. No. 5,453,098 (U.S. Ser. No. 08/241,041, filed May 9, 1994) discloses a fluid flow stop which protects against unintended actuation with a locking mechanism. The locking mechanism, however, somewhat complicates the user interface by requiring a two-step process. At a minimum, two hands are needed to manually manipulate the locking mechanism.
A product available from Medex Inc., known as the Trilogy.TM. Multichannel Infusion Pump, includes an optional flow clip on the disposable IV administration sets for use with the infusion pump. The flow clamp is a single piece of deformable plastic with two extending members that must be spread apart by the pump to open the tube, similar to a clothespin arrangement. In the relaxed state, the flow clamp occludes all flow of liquid through the tube. This structure is difficult to adapt for manual use, due to the fact that it is more difficult to spread two members apart, rather than pushing them together. In addition, the default to occluding the tube may lead to the permanent deformation of both the clamp and the tube itself.